I'm really interested to see how your brakes hold up after the StopTech's with ducting.
Thanks again.

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Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."

I just bought a set of 3" alu flanges and I'm planning on doing the brake duct mod.

I plan to cut & fit them to the underbody panel, then anodize them black and use OEM fasteners to secure them into the panel. I'm thinking of providing the brake ducting just into the wheel well plastic shroud, without going all the way to a backing plate. My reasoning is that my previous BMW's all had this type of arrangement and I was fine at the track when using track pads.

I just bought a set of 3" alu flanges and I'm planning on doing the brake duct mod.

I plan to cut & fit them to the underbody panel, then anodize them black and use OEM fasteners to secure them into the panel. I'm thinking of providing the brake ducting just into the wheel well plastic shroud, without going all the way to a backing plate. My reasoning is that my previous BMW's all had this type of arrangement and I was fine at the track when using track pads.

My vote for best thread on the forum. Great work OP. RRT used to make an economical kit for the E46 M3 but have nothing for the E92. My hose should arrive today and I'll play around with it this weekend to come up with a routing that will work for track days but not permanent. I don't have your patience anymore.

Anyone that's done this having issues with brake ducts getting pinched or damaged with full steering lock? My E36 has bimmerworld brake ducts in two sections... one from the front bumper to a flange in the fender liner, and another section that I usually leave disconnected that goes from the fender liner to the backing plate. If I use full steering lock the duct gets pinched or torn so that section is only for the track.

I like those turner inlets, but that's a bit pricey compared to hacking in something generic. Ditto on bimmerworld's $250 (per side) CF backing plates, but at least those aren't just plastic.

BTW, the inlets seen on those racecars are called NACA ducts. It's a shape that was found in aircraft research in the quest to bring air into a flat surface with minimum drag. Pegasus sells generic plastic ones in different sizes for around $20. For that matter they have generic rectangular air inlets for $23.

If you're worried about critters getting in, then it shouldn't be too hard to work in some wire mesh (aka chicken wire :-)

They also kind of defeat the purpose of the cheap brake cooling plan. My flanges from aircraft spruce were like $10 and do the same job. The Apex ducts may flow slightly better, but definitely not worth 20x. I did this DIY with success. The hard part is getting the hose to not rub when turning (especially parking).

They also kind of defeat the purpose of the cheap brake cooling plan. My flanges from aircraft spruce were like $10 and do the same job. The Apex ducts may flow slightly better, but definitely not worth 20x. I did this DIY with success. The hard part is getting the hose to not rub when turning (especially parking).

Here are a few. I don't have any of the undertray in detail, but I did it just like Junior did. I have ran the ducts for about 3 months off and on. I take the hoses off when I'm not going to the track and just leave the hole there. It rubs past 1 turn either way. Not an issue on track, but is annoying in city driving. I used them at Barber and VIR and had no issues with pinching or tearing etc. I don't have data on how much they helped cooling, but can't hurt. Probably won't run them with my ST60's now because I doubt I can fade those even without ducts. Everyone that has seen the car thinks they're aftermarket from some tuner or OEM (now that I painted the rivets black anyway ).